Method with_aggregate_function

datafusion/sql/tests/common/mod.rs:84–94

(
        mut self,
        aggregate_function: Arc<AggregateUDF>,
    )

    }

    pub fn with_aggregate_function(
        mut self,
        aggregate_function: Arc<AggregateUDF>,
    ) -> Self {
        // TODO: change to to_string() if all the function name is converted to lowercase
        self.aggregate_functions.insert(
            aggregate_function.name().to_string().to_lowercase(),
            aggregate_function,
        );
        self
    }

    pub fn with_window_function(mut self, window_function: Arc<WindowUDF>) -> Self {
        self.window_functions